This invention relates generally to a collapsible vehicle such as a bicycle and more particularly to a bicycle that may be collapsed in a single motion to significantly reduce the size of the bicycle for shipping and/or storage.
The present invention is a collapsible vehicle such as a bicycle designed to provide improved rigidity in its construction while minimizing the space required to store or ship the bicycle. Size reduction is preferably accomplished by an improved, pivoting design wherein the frame include angled elements that allow the bicycle frame to be collapsed to a point where the front and rear wheels of the collapsed bicycle are generally adjacent one another.
Heretofore, a number of patents and publications have disclosed various folding bicycle configurations, the relevant portions of which may be briefly summarized as follows:
Various folding bicycle configurations disclose embodiments where a front frame pivots relative to a rear frame. For example, U.S. Pat. No. 4,448,437 and U.S. Pat. No. 6,135,478, to Montague disclose a folding bicycle wherein the bicycle is collapsed by pivoting a front and rear frame relative to one another about the set down tube. U.S. Pat. No. 5,590,895 to Hiramoto, issued Jan. 7, 1997, teaches a collapsible bicycle frame where a front frame pivots about a hinge to fold the front wheel and head tube adjacent to the rear wheel and frame. U.S. Pat. No. 5,785,338 to Chang, issued Jul. 28, 1998, depicts a collapsible bicycle where a rear end of the front frame pivots relative to the rear frame so as to collapse with handle bars adjacent the rear wheel.
U.S. Pat. No. 6,032,971 to Herder, issued Mar. 7, 2000, discloses a folding bicycle where all of the pivoting members have horizontal pivot axes and are indirectly connected to a single collar that slides up and down a seat post.
Similar collapsible vehicle designs are depicted on various websites, including, for example, htt://www.pbwbikes.com/foldmtb.html, Copyright 2000, Peregrine Bicycle Works, Inc.
Generally, prior art collapsible bicycle designs require an operator to latch, tighten, or otherwise secure at least one hinged joint or element of the bicycle in order to make sure it is safe to operate and that the structure has sufficient rigidity to support an operator. As will be understood from the following description, the present invention seeks to overcome some of these drawbacks and to provide an improved collapsible bicycle design that may be folded or opened in a single motion.
In accordance with the present invention, there is provided a two-wheeled vehicle, comprising: a first wheel rotatably affixed to an axle passing therethrough; a drive wheel rotatably affixed to an axle passing therethrough; a steering assembly operatively connected to the axle of the first wheel so as to cause the first wheel to pivot about a generally vertical axis under the control of an operator, thereby enabling the first wheel to change the direction of the two-wheeled vehicle; a down tube having a first end slidably connected to said steering assembly, and a second end suitable for connection to said drive wheel; a seat assembly including a first end pivotably connected to said first longitudinal member and a second end upon which a seat to support the operator is adjustably attached; and a horizontal stay having a first end slidably connected to said seat assembly, and a second end pivotably affixed to said steering assembly, wherein the two-wheeled vehicle may be collapsed to a smaller size by slidably moving the down tube and horizontal stay members relative to the steering and seat assemblies, respectively.
In accordance with another aspect of the invention, there is provided A bicycle, comprising: a front wheel rotatably affixed to a steering assembly, wherein the steering assembly enables a user to change direction of the bicycle; a down tube having both a pair of chain stays and a pair of seat stays, said down tube being slidably connected to said steering assembly; a drive wheel rotatably affixed between the chain and seat stays of said down tube; a seat assembly including a first end pivotably connected to said down tube and a second end upon which a seat to support the operator is adjustably attached; a horizontal stay pivotally connected near its center to the down tube, slidably connected at one end to the seat assembly and pivotally connected at the opposite end to the steering assembly; wherein the down tube is pivotably attached to a slidable sleeve of the steering assembly and where the pivotably attached down tube in combination with the slidable sleeve, allow the bicycle to be collapsed.
One aspect of the invention deals with a basic problem often encountered with collapsible bicycles, that of providing a stable and secure structure for the xe2x80x9cassembledxe2x80x9d bicycle. Another aspect of the present invention deals with a problem of collapsing the bicycle so as to move the front and rear wheels to a position essentially adjacent one another. Such a configuration allows for more compact storage, and may further provide an easier means of transporting the collapsed bicycle by rolling it on its wheels. In particular, various designs rely on pivots and locking mechanisms that compromise the structural rigidity and safety of the assembled unit, or require hand tools to open or collapse the bicycle.
These aspects are further based on the discovery of techniques that alleviate the known problems. The technique provides for a collapsible bicycle that is structurally rigid yet does not require tools to complete the xe2x80x9cassemblyxe2x80x9d before an operator may ride the bicycle. In particular, the technique employs a plurality of slidable and pivotable joints to interconnect elements of the bicycle that allow the bicycle to be folded or opened in a single motion.
The techniques described herein are advantageous because they result in a simple, easy-to-assemble bicycle that can be stored in an upright storage location (e.g., closet), standing under its own support and requiring minimal space. Further advantages of the invention are a fully adjustable handle-bar (steering) and seat so as to provide a collapsible bicycle that is easily customized to the size of the operator.